Internationalized Domain Names -

Transcription

1 Internationalized Domain Names - Getting them to work Gihan Dias LK Domain Registry

2 What is IDN? Originally DNS names were restricted to the characters a-z (letters), 0-9 (digits) and '-' (hyphen) (LDH) Most languages use many other characters accents and additional characters in Latinbased languages non-latin scripts IDN is a method of using domain names in other scripts while maintaining compatibility with the ASCII DNS

3 IDN is An abbreviation for Internationalized Domain Name A domain name where at least one character is outside the Letter-Digit-Hyphen set used in the original DNS Based on Unicode (ISO 10646) characters Major transition from 38 ASCII characters to thousands of Unicode characters

4 Why IDNs? Largest number of Internet users now in the Asia- Pacific Growing number of users not familiar with ASCII or prefer to use their own script Using ASCII Domain names is significant linguistic barrier Native speakers of Arabic, Chinese, Japanese, Russian, Hindi, Tamil, Thai and others at considerable disadvantage Some names cannot be clearly expressed in Latin Need to provide a seamless experience without toggling keyboards and typing unfamiliar characters

5 The web content is in local language

6 How IDN works Uses ASCII characters on the wire between clients and servers no change to the original DNS protocol used in thousands of servers URLs based on Unicode (ISO 10646) characters possible to also use legacy character sets Applications (e.g. web browsers) convert the Unicode labels to ASCII Called Internationalizing Domain Names in Applications (IDNA)

7 Punicode A case folding and normalization process Unicode strings converted to ASCII Compatible Encoding (ACE) (and back) using Punicode algorithm Domain labels starting with xn-- represent ACE encoded internationalized label One-to-one correspondence between (normalised) Unicode label and ACE (Punicode)

8 Examples of Punicode conversion Unicode string ascii.com 日 本 語.jp தமழ.in bücher.de සහලidn.lk ACE string ascii.com xn--wgv71a119e.jp xn--rlcus7b3d.in xn--bcher-kva.de xn--idn-u4k9u8ai4i.lk

9 Issues in representing Indic languages with IDNA 2003 A major issue is the handling of the zerowidth joiner (ZWJ) and zero-width non-joiner (ZWNJ) characters These characters are used by most Indic scripts In some cases their use is optional (i.e. may change the appearance - but not the meaning - of a word) In other cases they are required Omitting them will give an incorrect spelling or change the meaning

10 IDNA2003 Issues (cont.) IDNA2003 silently deletes ZWJ, ZWNJ and other control characters Results in some labels not displaying correctly e.g. ශ ශර ZWJ 0DC1 0DCA 200D 0DBB 0DD3 0DC1 0DCA 0DBB 0DD3 More than one Unicode label may map to the same Punycode label

11 Phishing issues Inter-script similarity Certain letters in one script are similar (basically identical) to other letters in another script e.g. Latin a, Cyrillic а Intra-script similarity letter and numeral (or symbol) may look same e.g. Tamil அ (a) and Tamil ௮ (8) two letters may look similar e.g. Sinhala ඬ and ද

12 Browser issues Current browsers handle Unicode and automatically convert to Punicode May display punicode in URL bar instead of Unicode anti-phishing feature can be disabled via registry entry Some sites (e.g. Google) delete ZWJ/ZWNJ in search results not an IDN issue, but annoying

13 Entering domain names Indic text is complex Some letters may need multiple keystrokes to enter e.g. ක is entered using 4 keystrokes

14 IDN Process in Sri Lanka Sri Lanka formed an IDN task force ICT Agency of Sri Lanka Telecom Regulatory Commission Official Languages Dept., Ministry of S & T, LK Domain Registry, ISPs, Universities, etc. First task local lang. versions for.lk Identified potential strings Conducted Public Consultation

15 IDN Process (cont.) Obtained letters of support Submitted strings to ICANN Currently in evaluation process

16 IDN cctld Issues Labels for.lk in Sinhala and Tamil short, meaningful?, acceptable How many letters in a label? what is a letter? Decided to use the full country name.ල (.lanka) Sinhala (4 keystrokes).இலஙக (.ilangei) Tamil (6 keystrokes)

17 Selecting IDNs domains for organizations Names should be meaningful, easy to remember and easy to type Sinhala / Tamil names tend to be longer (in keystrokes) than English ones Abbreviations are less common in Sinhala/Tamil some org. names sound strange when abbreviated e.g. ICT Agency icta.lk => ක සන.ල Translate or Transliterate?

18 Selecting IDN strings for service names (e.g. www) www is a strange string meaningless difficult to pronounce How do we represent it in our language? don't translate www pick a string which clearly says website How about mail, rss, chat, proxy, etc.?

19 IDNA 2008 Uses a different paradigm from IDNA 2003 Most alphanumeric Unicode characters (except a few specified ones) are valid Applications (browsers) handle string mapping Registries handle registration restrictions Most differences between IDNA 2003 and IDNA 2008 are minor, except IDNA 2008 allows ZWJ/ZWNJ in certain contexts a few characters have different behaviour

20 IDNA 2008 More information in tomorrow's tutorial

21 IDN Registration Policies Registries (not only TLDs) need policies and procedures for: Handling of Indic numerals Unused and archaic letters Similar sounding letters Mixed-script labels Inter-label script mixing

22 LK Domain Registry Policies No registration of Indic numerals Registration limited to contemporary letters should be able to register all company names, trademarks,... No decision on similar-sounding letters bundling? Allow registration of similar-looking letters e.g. බ, ඛ ජ, ඡ etc. ZWJ only in specific contexts more restrictive than IDNA 2008

23 LK Registry Policies (cont.) Allow Latin+Sinhala and Latin+Tamil mixed script labels but no Sinhala+Tamil for now No inter-label script mixing Only register valid Unicode strings

24 LK Policies - Phishing No room for inter-script phishing only allow Latin+Indic no Latin letters similar to Indic Intra-script phishing possible we don't register numerals or symbols but some letters similar to others e.g. (බ, ඛ; ව, ච; එ, ඵ) users should be educated bundling/reservation may be done

25 Domain Selection Guidelines No guidelines at present Sinhala/Tamil acronyms not common Recommend to select most significant word or words as domain name

26 Discussion